This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-042970, filed Feb. 21, 2000, the entire contents of which are incorporated herein by reference.
This invention relates to a novel chiral molecular magnet, and also to a method of manufacturing such a chiral molecular magnet.
A phenomenon called xe2x80x9cMagneto-Chiral Dichroismxe2x80x9d has been known to occur in a chiral molecular magnet (magnetic material) as reported by G. Wagniere and A. Meier, xe2x80x9cTHE INFLUENCE OF STATIC MAGNETIC FIELD ON THE ABSORPTION COEFFICIENT OF A CHIRAL MOLECULExe2x80x9d, Chemical Phys. Lett. Vol 93, pp.78-81(1982); by G. Wagniere, Chemical Phys. Lett, Vol 110, pp.546-550(1984); and by L. D. BARRON, J. VRBANCICH, xe2x80x9cMagneto-chiral birefringence and dichroismxe2x80x9d, Mol Phys., Vol.51, pp.715-730(1984). According to these publications, an actual substance is not referred to, but only theoretical studies are set forth therein. Namely, this xe2x80x9cMagneto-Chiral Dichroismxe2x80x9d is reported as being one kind of magneto-optical effect, exhibiting characteristics that the absorbency and luminous intensity of crystal can be controlled for instance by the direction of magnetization of crystal and by the advancing direction of light. Accordingly, since this optical characteristics can be controlled by the direction of magnetic field, versatile applications thereof are expected in various fields such as optical communication and optical technology.
Meanwhile, Japanese Patent Unexamined Publication H9-246044 discloses a molecular magnetic material comprising a cobalt-iron cyano complex exhibiting the characteristics that the magnetic property thereof can be altered by the irradiation of light, and that the magnetic property thereof after the irradiation of light can be varied by the changes in temperature.
Japanese Patent Unexamined Publication H10-32111 discloses a molecular mixed magnetic material comprising at least one kind of magnetic ion unit of molecular magnetic material exhibiting a ferromagnetism and at least one kind of magnetic ion unit of molecular magnetic material exhibiting a ferrimagnetism, which can be represented for example by (Fe0.4Mn0.6)1.6Cr(CN)6, and whose magnetic property is variable by the irradiation of light.
Japanese Patent Unexamined Publication H10-208924 discloses a molecular magnetic material consisting for example of manganese(II)(tetraethoxyphenylporphyrin) tetracyanoethylene, and exhibiting a crystal magnetic anisotropy wherein the spin interaction in the direction of one-dimensional spin array is quite opposite to the spin interaction of an axis intersecting the aforementioned one-dimensional spin array.
An object of the present invention is to provide a chiral molecular magnet having characteristics exhibiting a monocrystal, a magnetic property, an optical activity, a transparent color and a relatively high transition temperature.
Another object of the present invention is to provide a method which makes it possible to manufacture a chiral molecular magnet having a monocrystal of relatively large size and the aforementioned excellent properties at room temperature and with a high yield.
Namely, according to this invention, there is provided a chiral molecular magnet formed a monocrystal and represented by a general formula [Mn(L)]3[Cr(CN)6]2.4H2O (wherein L is optically active (R or S)-1,2-diamines and derivatives thereof or optically active (R or S)-1,3-diamines and derivatives thereof).
There is also provided a method of manufacturing a chiral molecular magnet, which comprises the steps of;
preparing a solution of a diamine compound by dissolving an optically active diamine compound selected from the group consisting of optically active (R or S)-1,2-diamines and derivatives thereof, and optically active (R or S)-1,3-diamine and derivatives thereof in a completely deaerated solvent under a non-oxidative atmosphere;
preparing a solution of manganate salt by dissolving manganate salt in a completely deaerated solvent under a non-oxidative atmosphere;
mixing the solution of a diamine compound with the solution of manganate salt under a non-oxidative atmosphere to obtain a mixed solution;
preparing a solution of hexacyanochromate salt by dissolving hexacyanochromate salt in a completely deaerated solvent under a non-oxidative atmosphere;
performing a reaction between the hexacyanochromate salt and the mixed solution by mixing the solution of hexacyanochromate salt with the mixed solution under a non-oxidative atmosphere to obtain a reaction mixture; and
leaving the reaction mixture to stand at room temperature, thereby precipitating a monocrystal represented by a general formula [Mn(L)]3[Cr(CN)6]2.4H2O (wherein L is optically active (R or S)-1,2-diamines and derivatives thereof or optically active (R or S)-1,3-diamines and derivatives thereof).
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.